Semi-portable swimming pool

ABSTRACT

A semi-portable low profile readily expandable therapy pool or swimming pool is disclosed in which the side wall height is reduced while desirable pool depth is maintained by using virgin ground as a portion of the side wall and in which side wall structural strength requirements are reduced by constructing the side walls partially above and partially below ground level.

United States atent [191 Ancewicz et a1.

SEMI-PORTABLE SWIMMING POOL Inventors: Walter J. Ancewicz, 4828 KingwoodWay, San Jose, Calif. 95124; Orville H. Marsh, 6125 Prospect Road, SanJose, Calif. 95129 Filed: July 21, 1971 Appl. No.: 164,726

US. Cl ..4/l72.l9, 52/169 Int. Cl ..E04h 3/16, E04h 3/18 Field of Search..4/172, 172.19, 172.21;

References Cited UNITED STATES PATENTS Gabrielli et a1 ..4/172. 19

Schwarz et a1 ..4/172.21 X

[451 May 29, 1973 FOREIGN PATENTS OR APPLICATIONS Stern et a1. ..4/17210/1970 Germany ..4/172 Primary Examiner-Henry K. Artis Attorney-NormanE. Reitz and Hubert E. Dubb [5 7] ABSTRACT A semi-portable low profilereadily expandable therapy pool or swimming pool is disclosed in whichthe side wall height is reduced while desirable pool depth is maintainedby using virgin ground as a portion of the side wall and in which sidewall structural strength requirements are reduced by constructing theside walls partially above and partially below ground level.

5 Claims, 6 Drawing Figures I SEMI-PORTABLE SWIMMING POOL BACKGROUND OFTHE INVENTION This invention relates to semi-portable reservoirs, tanksor pools and, more particularly, relates to a low profile readilyexpandable swimming pool or therapy pool constructed partially above andpartially below ground level.

A traditional method of constructing swimming or therapy pools has beento excavate a volume of earth to form a cavity. Reinforced cement wallsor other structural means are used to shore up the sides of the cavityso that the earth surrounding the cavity does not collapse into thecavity. The reinforced walls also had to be strong enough to preventwater in the swimming pool from rupturing the sides. This type ofconstruction involved the utilization of costly materials and labor.Furthermore, once a traditional swimming or therapy pool is constructed,it is impossible to readily vary its size.

Above ground or portable swimming or therapy pools were introduced toreduce the cost of construction and the elfort involved in setting up apool. Above ground pools could be moved from place to place andconsequently, were less expensive than sunken pools. The walls of suchpools however were necessarily shored up to support the weight of thewater within the pool. Furthermore, such pools were subject to washoutaround the bottom edge of the pool where the exterior of the pool camein contact with the ground. Such pools presented a safety problem sinceswimmers could fall from walkways built around the pool to the groundoutside the pool, adults could not readily see into the pools todetermine whether children were in trouble inside the pools, andneighbors can look over fences and observe swimmers or therapy patientsusing the pool.

It is therefore an object of this invention to reduce the wall height ofa semi-portable swimming or therapy pool and still obtain the desirabledepth by employing virgin ground as a portion of the side wall.

It is also an object of this invention to provide a low profile swimmingor therapy pool in which the structural strength required for the poolwalls is minimized by constructing the walls partially above andpartially below ground level.

It is a further object of this invention to provide a semiportableswimming or therapy pool which can be readily expanded by removal of awatertight plastic liner and further excavating the bottom of the poolor by extension of the height of the swimming pool walls.

It is a further object of this invention to provide a low profilesemi-portable swimming pool wherein washout of the ground surroundingthe exterior of the pool is eliminated.

It is an additional object of this invention to provide a swimming poolhaving steps on the interior thereof wherein the shelf on which therecessed side wall rests serves as a step support.

It is a still further object of this invention to provide asemi-portable swimming pool which employs horizontally disposed ratherthan vertically disposed structural supports for the portion of theswimming pool walls extending above the ground.

SUMMARY OF THE INVENTION A cavity of sufficient depth to constitute asignificant portion of the height of a tank, reservoir, swimming pool orthe like is excavated. The contour of the cavity is dependent upon thepurpose the tank or pool is designed to serve, the type of groundencountered, and the presence or absence of a firm filler material. Ashelf is excavated in the ground around the perimeter of the cavity to aslight depth on the order of one foot. A side wall fabricated from woodor lightweight metal is placed on the shelf around the pool. The flushfitting of the side wall with the virgin ground adjacent the shelfeliminates the settling problems encountered with the uncompacted earthleft by excavate and fill construction methods. The height of the sidewall above the ground typically ranges from 1 to 3 feet.

The contoured bottom of the semi-portable swimming pool is covered witha layer of a flexible plastic material such as polyvinylchloride whichis detachably attachable to a track running along the inside edge of theperimeter of the side wall. Structural strength requirements for thewall are reduced by the fact that earth pressure against the bottom ofthe side wall is not especially great since the wall is set to only aslight depth in the ground and by the fact that only the small portionof the side wall above the ground is subject to pressure due to theenclosed volume of water. The portion of the wall above ground issupported preferably by a horizontally disposed external clamping meanssuch as a cable, series of bolted planks, or the like.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cut-away perspective viewof the readily expandable semi-portable swimming pool of the presentinvention.

FIG. 2 is a detailed side view of a traditional low profile swimmingpool including shoring members illustrating the refilled ground aroundthe pool.

FIG. 3 is a detailed cross-sectional view of one side of thesemi-portable swimming pool of the present invention.

FIG. 4 is a cross-sectional end view of the readily expandablesemi-portable swimming pool of the present invention illustrating inphantom a number of potential bottom contours.

FIG. 5 is a side view of a horizontally disposed wall support and aseries of interim steps incorporated in the semi-portable swimming poolof the present invention.

FIG. 6 is a detailed cross-sectional view of the upper end of aretaining wall of the semi-portable swimming pool of the presentinvention illustrating an anti-splash coping, vinyl liner track andvinyl liner bead.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 1 it canbe seen that side wall 13 which spans the perimeter of the semi-portableswimming pool accommodates only a portion of the total depth of thepool. The upper portion of side wall 13 extends above ground level 12while the lower portion rests on a shelf 14 which has been excavatedfrom virgin ground around the perimeter of the swimming pool cavity.Widely spaced, conventional A-frame supports 11 are sufficient tosupport the outward force of water within the pool since the majorportion of the volume of water within a filled pool presses against thevinyl liner and thence against the surrounding virgin ground. Theevident low profile of the swimming pool creates easy access to the pooland visibility of activities taking place within the pool.

FIG. 2 illustrates a low profile swimming pool of the prior art. Theprior art low profile pool is constructed by excavating a cavity andplacing a side wall 21 on the bottom with surrounding supportingstructures 9. Then, typically, the excavated earth is replaced toprovide additional support for the walls of the pool. This method ofconstruction requires considerably more excavation than the method ofthe present invention and leaves refilled ground 22 surrounding the lowprofile swimming pool. This refilled ground can become soggy andunstable and may subsequently settle. Ifthis occurs side wall 21 canrupture inwardly when the pool is drained.

Side wall 27 of the readily expandable semi-portable swimming pool ofthe present invention is shown in detail in FIG. 3. A cavity isexcavated and a compacted filler material 26 such as sand, zonolite orother similar material is thinly spread over a portion of the cavity. Ashelf 8 is then excavated around the perimeter of the cavity to supportretaining wall 27. Exterior side 7 of retaining wall 27 abutts virginground. The inside surface of retaining wall 27 fits flush with theouter surface of the filler material 26 so that a unitary plastic liner28 may be fitted over the inside of the swimming pool. The bulk of theweight of the water is directed toward the virgin ground surrounding thecavity and the above ground portion of retaining wall 27 experiencesminimal forces so that external supports need not be especially strong.Indeed, in an embodiment of the invention, described infra, ahorizontally disposed external structural support is adequate tocounteract these outward forces. There is virtually no washout problemsince retaining wall 27 is snuggly fitted into virgin rather thanrefilled ground. And there will be no tendency for the groundsurrounding the pool to cave inwardly when the pool is drained since thesurrounding ground cannot become supersaturated with water.

FIG. 4 illustrates a number of contours for the bottom of thesemi-portable readily expandable swimming pool of the present invention.If an unconsolidated filler material such as sand is used underneath theplastic liner then contours A and C represent, respectively, thecontours of the shallow end and the deep end of the swimming pool.Curved corners are not possible because the unconsolidated fillermaterial will not remain in a stable curved position. If a consolidatedfiller material such as zonolite is used then contours B and Crepresent, respectively, the possible contours for a shallow end and adeep end of a swimming pool. The advantage of an unconsolidated fillermaterial is that it is easier to apply and remove than a consolidatedmaterial so that the readily expandable feature of the semi-portableswimming pool is more easily realized. However, the consolidated fillermaterial may still be incorporated with the subsequent realization ofthe readily expandable feature.

A great advantage of the semi-portable readily expandable swimming poolof the present invention is that the depth of the pool can be readilyincreased or decreased and the structural supports of the pool can beremoved to another location for subsequent construction. Since theretaining wall is not permanently sunk into the ground, the pool may bedrained, the plastic liner removed and the wall taken apart in sectionsand removed to another location. It can then be set on a similar shelfand incorporated into another swimming pool. If it is desired to leavethe swimming pool in the same location and to expand or contract thesize of the pool, e.g., from a wading to a standard sized pool, then theliner and filler material are removed and further excavation or fillingin is conducted. A new layer of filler material is then applied and anewly sized liner is placed in the pool. An additional method ofincreasing or decreasing the height of the pool is to add or cut off aportion of the retaining wall, although this procedure is morecumbersome than the further excavation or filling in of the swimmingpool bottom. Also, if additional height is added to the retaining wallthe exterior structural supports must be strengthened.

FIG. 5 illustrates the incorporation of a series of interior steps intothe swimming pool of the present inven' tion. The existence of theelongated shelf 39 facilitates the construction of steps 31 and 32.Shelf 8 of FIG. 3 is extended so that a step 32 can be supported on theexterior edge thereof. A slab of compacted material is used to constructstep 32. Filler material 34 is placed flush with the outer edge of thiscompacted material so that liner 33 can be fitted smoothly around thefiller material, compacted material and wooden or metal steps. A heavystabilizing material 36 such as crushed rock is placed in an interiorcavity underneath step 31 to add stability to the wall of the swimmingpool.

In lieu of A-frame or vertically constructed external supports for sidewall 30 horizontal shelf 37 can be used since no great outward pressuresexist even with a filled pool. External support is provided by a seriesof horizontal planks 37 which are bolted together along the exteriorsurface of side wall 30 and at the comers of the pool so that novertical supports are required. If the horizontal shelf 37 is to be usedas a step to reach the top of the swimming pool, as shown in FIG. 5,then a series of upright supports 38 should be added.

FIG. 6 shows the detachably attachable characteristic of the plasticliner of the swimming pool of the present invention. Bead 25 of plasticliner 33 fits into track 24 which extends around the perimeter of theswimming pool. When the opening of track 24 is pressed together the bead25 is held in place and the weight of the water in the pool will holdthe plastic liner taut. The inside portion of coping board 23 serves toprotect the upper portion of plastic liner 33 from ultravioletdegradation. The portion of liner 33 which is covered by water is notreached by direct sunlight but the portion of liner 33 between the topof the water and track 24 is reached by direct sunlight and therefore issusceptible to degradation. Coping board 23 serves to providesignificant protection.

The side wall height of the swimming or therapy pool of the presentinvention should be kept to a minimum to lessen construction costs,enhance portability and to insure the low profile character of the pool.The side wall should extend below ground level only far enough for it torest securely on the shelf along the perimeter of the excavated cavityand to solidly abut virgin ground. In practice one foot or less has beenfound satisfactory. The side wall should extend above ground far enoughto accommodate a portion of the height of the pool and yet not so farethat cumbersome external supports are required or the low profilecharacter of the pool is lost. In practice two feet or less has beenfound to be a satisfactory above ground extension of the side wall.

A specific set of features for the semi-portable readily expandableswimming pool of the present invention have been disclosed herein butthey are intended as examples only and the scope of this application forLetters Patent is intended to be limited solely by the scope and spiritof the appended claims.

We claim:

11. A readily expandable low profile semi-portable reservoir, tank orpool, comprising a continuous vertical side wall adapted to rest on arecessed shelf surrounding an excavated cavity, the lower exteriorportion of said vertical side wall abutting virgin ground below groundlevel, said vertical side wall forming an extension of a verticalearthen side wall formed in virgin ground around the side of saidexcavated cavity, the above ground exterior portion of said verticalside wall being supported by external supports, a uniform layer of afiller material covering said excavated cavity including said verticalearthen side wall formed in virgin ground, and a plastic linerdetachably attachable with the upper portion of the interior side ofsaid vertical side wall and form fitting the inside of said verticalside wall and the contour of said filler-covered cavity including saidvertical earthen side wall formed in virgin ground.

2. The readily expandable semi-portable tank or pool of claim 1 whereinsaid filler material is a consolidated material such as zonolite.

3. The readily expandable semi-portable tank or pool of claim 2 whereinsaid horizontally disposed member comprises a series of horizontallydisposed planks which are attached to each other and to said side wall,

said planks being in turn supported by upright supports.

4. A readily expandable semi-portable swimming or therapy pool forexpeditious and uncomplicated backyard construction, comprising a rigidupright side wall adapted to sit on a horizontal earthen shelf formedaround the perimeter of the cavity excavated in a generally horizontalground surface, said rigid upright side wall extending above groundlevel about 2 feet and extending below ground level about 1 foot, theexterior portion of said upright side wall which extends below groundlevel abutting said ground, said upright side wall forming an extensionof a vertical earthen side wall formed in virgin ground around the sideof said excavated cavity, a horizontal coping member attached to theupper end of said upright side wall in perpendicular relationship tosaid side wall and extending beyond the interior side thereof, a fillermaterial spread evenly over the contour of said cavity including saidvertical earthen side wall below the bottom of said upright side wall ata thickness of 1 inch to 4 inches, and a vinyl liner detachablyattachable with a longitudinal track member which runs along the insiderim of the upper portion of said upright side wall, said vinyl lineradapted to conform to said side wall and said fillercovered contouredbottom including said vertical earthen side wall.

5. The readily expandable semi-portable swimming or therapy pool ofclaim 4 in combination with a series of steps adapted to rest interiorlyof said side wall on an extension of said horizontal earthen shelf.

1. A readily expandable low profile semi-portable reservoir, tank orpool, comprising a continuous vertical side wall adapted to rest on arecessed shelf surrounding an excavated cavity, the lower exteriorportion of said vertical side wall abutting virgin ground below groundlevel, said vertical side wall forming an extension of a verticalearthen side wall formed in virgin ground around the side of saidexcavated cavity, the above ground exterior portion of said verticalside wall being supported by external supports, a uniform layer of afiller material covering said excavated cavity including said verticalearthen side wall formed in virgin ground, and a plastic linerdetachably attachable with the upper portion of the interior side ofsaid vertical side wall and form fitting the inside of said verticalside wall and the contour of said filler-covered cavity including saidvertical earthen side wall formed in virgin ground.
 2. The readilyexpandable semi-portable tank or pool of claim 1 wherein said fillermaterial is a consolidated material such as zonolite.
 3. The readilyexpandable semi-portable tank or pool of claim 2 wherein saidhorizontally disposed member comprises a series of horizontally disposedplanks which are attached to each other and to said side wall, saidplanks being in turn supported by upright supports.
 4. A readilyexpandable semi-portable swimming or therapy pool for expeditious anduncomplicated backyard construction, comprising a rigid upright sidewall adapted to sit on a horizontal earthen shelf formed around theperimeter of the cavity excavated in a generally horizontal groundsurface, said rigid upright side wall extending above ground level about2 feet and extending below ground level about 1 foot, the exteriorportion of said upright side wall which extends below ground levelabutting said ground, said upright side wall forming an extension of avertical earthen side wall formed in virgin ground around the side ofsaid excavated cavity, a horizontal coping member attached to the upperend of said upright side wall in perpendicular relationship to said sidewall and extending beyond the interior side thereof, a filler materialspread evenly over the contour of said cavity including said verticalearthen side wall below the bottom of said upright side wall at athickness of 1 inch to 4 inches, and a vinyl liner detachably attachablewith a longitudinal track member which runs along the inside rim of theupper portion of said upright side wall, said vinyl liner adapted toconform to said side wall and said filler-covered contoured bottomincluding said vertical earthen side wall.
 5. The readily expandablesemi-portable swimming or therapy pool of claim 4 in combination with aseries of steps adapted to rest interiorly of said side wall on anextension of said horizontal earthen shelf.